Is Processed Flour Inflammatory? What You Need to Know

November 19, 2025 •

3 min read

According to a 2022 study, increasing intake of ultra-processed foods (UPF) is directly associated with low-grade inflammation. This has led many to question whether processed flour, a common ingredient in UPF, is inflammatory and what the precise mechanisms are.

Quick Summary

This article explores the link between processed flour, its high glycemic index, and chemical additives, detailing how these factors can contribute to chronic inflammation. It also covers the differences between refined and whole grain flours and provides healthier alternatives.

Key Points

Refining Process: Processed flour is stripped of the bran and germ, removing most fiber and nutrients, leaving behind starchy endosperm.
Blood Sugar Spikes: The high glycemic index of refined flour causes rapid blood sugar fluctuations and insulin spikes, a key driver of inflammation.
Gut Health Impacts: A diet high in refined flour can negatively impact the gut microbiome and increase intestinal permeability, leading to systemic inflammation.
Chemical Additives: Some processed flours contain bleaching agents and other additives that may induce oxidative stress and further contribute to inflammation.
Healthier Alternatives: Substituting processed flour with whole grains or nutrient-rich alternatives like almond, coconut, or quinoa flour can help reduce inflammation.
Chronic vs. Acute: Occasional consumption of processed flour is unlikely to be harmful, but chronic, regular intake is linked to long-term inflammatory conditions.

The Refining Process: What Is Removed from Flour?

Processed flour, often labeled as white or all-purpose flour, undergoes a milling process that removes the bran and germ from the whole grain, leaving only the starchy endosperm. This refining strips away most of the fiber, vitamins, minerals, and beneficial phytochemicals found in the whole grain. While some nutrients are added back in an 'enrichment' process, it doesn't match the nutritional value of the original whole grain. The lack of fiber and high simple carbohydrate content is a key reason processed flour is linked to inflammation.

The High Glycemic Index and Blood Sugar Spikes

Refined carbohydrates like processed flour are quickly digested, leading to rapid increases in blood sugar. This triggers the release of insulin to regulate the sugar. Frequent blood sugar spikes and subsequent insulin surges can contribute to insulin resistance and chronic low-grade inflammation over time.

Chemical Additives and Gut Health Disruption

Processed flour can contain chemical additives, such as bleaching agents like benzoyl peroxide, which may cause oxidative stress. Diets high in foods containing refined flour and other additives can negatively affect the gut microbiome. An imbalanced gut can lead to increased intestinal permeability, potentially allowing harmful substances to enter the bloodstream and trigger systemic inflammation.

Refined vs. Whole Grain Flour: A Comparison

Understanding the differences between processed and whole grain flour highlights why whole grains are generally preferred for an anti-inflammatory diet.


Feature	Processed Flour (e.g., White Flour)	Whole Grain Flour
Nutrient Content	Stripped of most nutrients; synthetically 'enriched'.	Contains the whole grain, including bran and germ, retaining fiber, vitamins, and minerals.
Fiber	Very low fiber content (approx. 0.9g per 1/4 cup).	High fiber content (approx. 3.5g per 1/4 cup).
Glycemic Index (GI)	High GI, causing rapid blood sugar spikes.	Lower GI due to fiber, resulting in a slower, more stable blood sugar release.
Inflammatory Potential	High; linked to chronic, low-grade inflammation.	Lower; associated with reduced inflammatory markers.
Impact on Gut	Can disrupt gut barrier and microbiome health.	Feeds beneficial gut bacteria and supports a healthy microbiome.

Healthier Alternatives to Processed Flour

Numerous whole grain and gluten-free flours provide better options for reducing inflammation.

Whole Grains

Whole Wheat Flour: Contains all parts of the wheat kernel for more fiber and nutrients.
Oat Flour: Rich in soluble fiber like beta-glucan, which can reduce inflammation.
Barley Flour: High in fiber with a lower glycemic index than refined flours.
Brown Rice Flour: Offers more nutrients and fiber than white rice flour.

Gluten-Free Options

Almond Flour: High in protein, healthy fats, and fiber with a lower glycemic impact.
Coconut Flour: A high-fiber, lower-carb choice with beneficial medium-chain triglycerides.
Quinoa Flour: A complete protein source, providing fiber and iron.
Buckwheat Flour: Rich in fiber, protein, and antioxidants.

Conclusion

While consuming processed flour occasionally may not cause noticeable inflammation, regular intake, especially as part of a diet high in ultra-processed foods, can contribute significantly to chronic inflammation. The refining process removes beneficial components, resulting in a high-glycemic product that can spike blood sugar and potentially disrupt gut health. Choosing whole grain or alternative flours supports stable blood sugar, promotes a healthier gut, and helps manage inflammation, contributing to an anti-inflammatory diet. Additional resources, such as those from the Arthritis Foundation, offer guidance on anti-inflammatory eating.

Frequently Asked Questions

White flour is considered inflammatory because the refining process removes its fiber and nutrients, leaving behind a high-glycemic starch. This causes rapid blood sugar spikes, which can trigger the body's inflammatory response over time.

Processed flour can negatively affect the gut by disrupting the balance of the gut microbiome and potentially increasing intestinal permeability, also known as 'leaky gut'. This allows bacteria and endotoxins to leak into the bloodstream, stimulating a systemic inflammatory response.

While processed flour is not a direct cause of joint pain for everyone, it can contribute to chronic inflammation, which is a known factor in conditions like arthritis. For those with gluten sensitivity, it may also trigger an inflammatory immune response that manifests as joint pain.

Healthy alternatives to white flour include whole grain options like whole wheat, oat, and barley flour, as well as gluten-free choices such as almond, coconut, quinoa, and buckwheat flour. These retain more nutrients and fiber, leading to a lower inflammatory impact.

While whole grains are generally less inflammatory than refined grains due to their fiber content and lower glycemic index, a balanced approach is key. The benefit of whole grains comes from their complete nutritional profile, but overall dietary context matters.

Regularly consuming high-glycemic foods made from processed flour can contribute to weight gain. Because they lack fiber, they are less filling, leading to overeating, and the resulting blood sugar spikes encourage fat storage.

Yes, it is acceptable to eat products with processed flour in moderation, especially if your overall diet is balanced and rich in fruits, vegetables, and whole grains. Chronic, long-term consumption is the primary concern for contributing to systemic inflammation and other health issues.